slack-vitess-r14.0.5: remove legacy sharding, add MySQL 8.x backup test + compressors

[timvaillancourt]

Description

This PR backports the deprecation of legacy resharding functionality from v15

Backporting this early has 3 x benefits:

1. It removes our most flaky CI test: Cluster (shardedrecovery_stress_verticalsplit_heavy)
2. Backports for vtorc depend on these PRs to be merged
   • Doing this in separate PRs to limit changes
3. It removes unused code and CI tests
4. It adds missing tests for MySQL 8.x, which is being 🚢'd to prod
5. It adds support for different backup compressors, something we manually patch today

cc @ejortegau to validate that we are not using legacy resharding (vtworker-based/no VReplication) functionality:

1. https://vitess.io/docs/archive/14.0/user-guides/historical/horizontal-sharding/ (SplitClone)
2. https://vitess.io/docs/archive/14.0/user-guides/historical/vertical-split/ (VerticalSplitClone)

If we are using legacy resharding, it's about to be removed in v15 😅

Related PR(s)

1. Delete all legacy sharding related code vitessio/vitess#10278
2. Remove v2 resharding fields vitessio/vitess#10409
3. Remove sharding_column_name and sharding_column_type from vtctld2 vitessio/vitess#10459
4. Backup/Restore: add support for external compressors and decompressors vitessio/vitess#10558
5. Add MySQL 8 Support to Backup Tests vitessio/vitess#10691

Checklist

• "Backport to:" labels have been added if this change should be back-ported
• Tests were added or are not required
• Did the new or modified tests pass consistently locally and on the CI
• Documentation was added or is not required

Deployment Notes

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @mattlord @arvind-murty to sign the Salesforce Inc. Contributor License Agreement.

[timvaillancourt]

I've confirmed our vtops codebase never calls the legacy sharding functions. They exist in vendor/ only:

tvaillancourt@tvailla-ltmxctu vtops % git grep SplitClone 
vendor/vitess.io/vitess/go/vt/binlog/binlogplayer/binlog_player.go:// workflow: documents the creator/manager of the stream. Example: 'SplitClone'.
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:// SplitClone initiates a SplitClone workflow.
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:func (wr *Wrangler) SplitClone(ctx context.Context, keyspace string, from, to []string) error {
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:                     cmd := binlogplayer.CreateVReplicationState("VSplitClone", bls, "", binlogplayer.BlpStopped, primary.DbName())
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:// VerticalSplitClone initiates a VerticalSplitClone workflow.
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:func (wr *Wrangler) VerticalSplitClone(ctx context.Context, fromKeyspace, toKeyspace string, tables []string) error {
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:     cmd := binlogplayer.CreateVReplicationState("VSplitClone", bls, "", binlogplayer.BlpStopped, primary.DbName())
vendor/vitess.io/vitess/go/vt/wrangler/keyspace.go:     return nil, nil, fmt.Errorf("neither Shard '%v' nor Shard '%v' have a 'SourceShards' entry. Did you successfully run vtworker SplitClone before? Or did you already migrate the MASTER type?", os.Left[0].ShardName(), os.Right[0].ShardName())

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @mattlord @arvind-murty @rsajwani to sign the Salesforce Inc. Contributor License Agreement.

[salesforce-cla]

Thanks for the contribution! Before we can merge this, we need @notfelineit @mattlord @arvind-murty @rsajwani to sign the Salesforce Inc. Contributor License Agreement.

[timvaillancourt]

A note: the salesforce-cla bot is insane and thinks the author of the upstream PRs we backport needs to sign our CLA. Please ignore this CI

[timvaillancourt]

@maksimov these backports change go-version from 1.19.3 -> 1.18.7. Were these changes you added and do we need to keep them? 🙇

[ejortegau]

I believe we need to keep it at 1.19.3+ for security vulnerabilities, but it's better to double check with Stas once he's back.